Frequency-selective filters can be used in a variety of applications. For example, a filter having a low-pass response in the frequency domain can be used for suppression of image frequencies when the filter is used as an interpolation filter, such as included as a portion of an oversampling sigma-delta digital-to-analog conversion circuit. The interpolation filter can be implemented as a digital filter, such as having a fixed stop-band attenuation and a fixed cut-off frequency. Generally, discrete-time filter characteristics such as filter type (e.g., frequency response, topology) and performance (e.g., stop-band attenuation, rate of roll-off, cut-off frequency) are established in relation to overall system specifications, and a corresponding filter parameters such as filter order are then fixed.